Green Wave Becomes Permanent on Valencia Street

Photo: Bryan Goebel

Valencia Street’s nearly two-year-old Green Wave signal re-timing aimed at prioritizing bicycle traffic speeds continues to please street users, city leaders, and advocates alike. What started as a temporary pilot will become a permanent institution this week with the installation of four new Green Wave signs along the corridor.

“Green Waves are the most recent example of the SFMTA finding innovative ways to further improve cycling in San Francisco,” said SFMTA CEO Nat Ford.

Following examples in cities like Copenhagen, Amsterdam, and Portland, the signal optimization keeps vehicles traveling at a steady cycle-friendly 13 mph from 16th to 25th streets while garnering benefits for all users.

“The Green Wave signals and the safer, calmer speeds are another step in the right direction for Valencia Street, which is already a thriving commercial corridor thanks to its wide sidewalks and bike lanes and plentiful on-street bike parking,” said Renee Rivera, acting executive director of the San Francisco Bicycle Coalition.

All-green lights provide a great convenience for bicycle travel, effectively removing the strenuous stop-and-go movement that often encourages passing through red lights. Along with pedestrians, cyclists also experience a much safer environment as motor vehicles travel at minimally fatal speeds as well as reduced noise and air pollution.

Photo: Bryan Goebel

Even motorists are able to drive more carefully as well as save gas and brake wear by traveling at a pleasantly steadier pace. An SFMTA study done prior to implementation projected average motor vehicle travel times would actually decrease.

The other more widely known Green Wave is Copenhagen’s Nørrebrogade, the busiest bicycle street in the Western world, carrying an average of 38,000 cyclists per day with bike lanes as wide as 16 feet. There, implementation of the green wave has also improved the flow of its heavy bus traffic.

The San Francisco Bicycle Coalition would like to some day see the increasingly popular Valencia Street become a bicycle corridor of similar significance to Nørrebrogade, with its vision for a two-way cycle track in the center of the street included in their Connecting the City campaign. With cars now traveling no faster than bicycle speeds, it would make sense.

San Francisco’s Green Wave is already unique because it is the first in the world to work two ways simultaneously, something Mayor Newsom calls “another example of our leadership in providing quality cycling improvements for this community.”

“Those who bike in San Francisco have seen their rides become safer and more efficient. Our continued commitment is to further the progress made and further establish San Francisco as a champion for providing multiple modes of transportation,” said Newsom.

The SFMTA said it was not currently considering expanding Green Wave to other bicycling corridors but is considering 14th Street for a pilot.

Check out Janel Sterbentz’s Streetfilm on Green Wave from 2009. Shortly after she wrote about Green Wave on Streetsblog, and lobbied the SFMTA with other advocates, the agency began re-timing the signals on Valencia.

Green Wave designations used on Copenhagen's Nørrebrogade. Photos via Copenhagenize and fietsberaad.nl.

  • Nick

    From Market to 16th Street, they should put up “You’re on Your Own” bike signs.

  • In my opinion the Valencia signal retiming is the most effective project SFMTA has implemented in recent years, actually helping people get where they’re going faster, more safely and more sustainably. It’s also one of the simplest and least expensive projects and benefits all modes simultaneously, at a time when transportation issues are always framed as hopelessly complex and divisive.

    It’s a shame that it sounds like there is little interest in retiming other streets or implementing signal preemption for transit vehicles. These really seem like the best possible investments you could make, providing massive ongoing benefits from trivial one-time investments.

  • bret

    I think the green timing of Valencia is great. Not sure 14th is the best next candidate. Given the one-way-ness and great starter hill 13mph seems a little slow for 14th.

  • Mark D.

    Just another project giving bikes a little more priority on our streets. Just like the new bike signals on Fell @ Masonic. Great work!!

  • JudyAlias

    I’ve enjoyed the Green Wave since its inception. Yes, it’s great to be able to ride for nine blocks without stopping. Am loving the side effects, as well: sailing through the light just as it turns green while passing the same jack-rabbit-start motorist block after block! (So I’m having mixed feelings about the new signage…)

  • Right now to make the lights on 14th street I have to go over 18 mph, which is faster than I am comfortable going. Yes, 13 mph might be a little slow from Dolores to Valencia, but 18 is too fast. And east of Valencia I’d be very happy with 13 mph.

    I think the Green wave signs are great.

  • Bombing 14th to make the lights is fun…if not a little scary watching out for doors and all…bringing the light speed down to 13-15mph would be great. Thanks due to Janel Sterbentz for kickstarting the Green Wave on Valencia.

    – J

  • Thanks are definitely due to Janel. I’m curious what other streets ya’ll think would work for Green Wave. Why not Folsom and Howard? 7th and 8th?

  • It would be nice if they could time Valencia St all the way to Market Street. (Why is it not?) Having timed lights set at lower speeds on Folsom and Howard would be great, but cars currently blast along those long blocks at about 30 – 40 mph now, so that would be a big, big reduction. I’d be really happy with 14th and 17th streets timed for bikes (once they put the bike lanes in on 17th.) That would actually tempt me to stop using 18th street (a flatter and happier street with less Muni tracks) and use 17th instead.

  • @taomom: but isn’t that even more reason to institute a green wave on folsom and howard? because those streets are treated like freeways right now? 🙂

  • SF Resident Engineer

    The benefits of the “green wave” extend well beyond bikes. When traffic signals along a corridor are timed this way, car speeds are reduced (which reduces noise and pollution) and cars can’t run red lights. Great for pedestrian safety, and great for business!

    This type of signal timing should be applied to streets beyond bike routes in order to improve pedestrian safety and reduce noise.

    The Mission has a square street grid and all the intersections from Guerrero to Folsom are signalized. That means 13mph signal timing could be applied in both directions on ALL streets in the Mission, both north/south and east/west streets. That would be a major improvement for the whole Mission, on the cheap! Transit-priority signals would hold the green for Muni.

  • Lucinda

    This sounds great. Don’t bike, but back when I had a car I would have LOVED to have nice, steady pace on a commercial street like this. And the signs showing the light timing – awesome. They need these on Great Hwy. Used to live out by the zoo, and it drove me nuts daling with people who didn’t realize the lights were timed. Tailgating, whipping around me to get to that red light first. Aargh.

  • I love timed signal. I haven’t bike much (nor drive much) on Valencia to experience it. But the driving experience on Franklin, Pine, and Bush is wonderful smooth sailing. The key is you have to drive under speed limit. This is really counter-intuitive to driver that you end up moving faster by driving slower. Most drivers act on their competitive instinct, end up hitting red light too soon and lost all the momentum, wear out the brake pad, and waste gas to start the car from idling.

    If the signal are timed at 13-15mph, you might as well set the speed limit to 13-15mph. This is going to be the effective speed anyway, no matter how hard people try to hit their gas pedal. And I think we need some education campaign so that people knows how to take advantage of the timed signal.

    I am also curious on the engineering technique to make signal timing works two way.

  • Tom

    Nice work. I ride Golden Gate from Macalester to Market and it is almost timed well for downhill (one way) biking. Some slight tweaks, especially starting at Gough would make this an easy third trial.

  • Eric Fischer

    Wai Yip Tung, it works two ways on Valencia just because the blocks are about the right length for the timing they wanted. The blocks are 600 feet long, so you can get 13 mph (19 feet per second) by having the lights change every 31.5 seconds.

    It’s harder to make it work for two-way traffic if the blocks are much shorter or the planned speed is much higher than that, because then you end up with a very quick signal cycle.

  • flacobrown

    ?!

  • “Green Wave”?

    IIRC, the light timing had nothing to do with making the ride easier for bicycles, that was just a happy accident. If my recollection of how this happened are correct, this seems a little bit of green-washing. Innovative accidents and selling unintended side effects as intended? No wonder there’s little interest in taking this ‘win’ elsewhere.

    Hopefully I’m wrong. Maybe they just couldn’t call it a bicycle-improvement during the injunction.

  • @roymeo, the second picture shows a green sign with a bicycle sign over the word “green wave”. I think it is lot more planned than a happy incident. Timed signal is great for traveling. I was initially very happy when the North Point bike was stripped. But I was quickly disappointed when I hit red light on every intersection. It sounds like the experience on Valencia will be much better.

  • @Eric,

    I see. So this also mean the amount of green light is 50/50 for both NS and EW traffic.

    In that case it won’t be applicable to Cesar Chavez where we want to keep the green on for longer portion of time. I’m not saying we should limit its speed to 13 mph. I’m just a big fan of timed signal and hope it will be implemented on main arteries.

  • Oh, don’t get me wrong, at the very least, Valencia is timed very well with a nice bicyclist pace and feels much like the Nørrebrogade (I was there this summer).

    But at the time it was presented as a happy accident that had nothing to do with bicycles, so I’m wondering if it was just ‘bikes on the downlow’ then, or if it’s opportunistic credit claming now?

    Either way, it worked to bicyclist’s advantage.

  • It doesn’t have to be exactly 50-50, as long as the duration is still reasonable for each direction, but I think in the case of Valencia it is. (You could have 35 seconds for one direction and 25 in the other, for instance, as long as the street wasn’t too wide for pedestrians to cross in 25 seconds.)

    The thing that actually keeps it from working well on Cesar Chavez is that you don’t just have a light every 600 feet, you also have one at Shotwell and Alabama. So either you have to do the calculation as if all the blocks were shorter, with consequently lower wave speeds, or you have to favor one direction or the other at these intersections, since their green lights need to come a quarter of the way through the 600-foot cycle and therefore at the wrong time (three quarters of the way through the cycle) in the other direction.

  • This is brilliant. Thank you SFMTA!

  • If anybody is interested, I plotted the average speeds on Valencia before and after the change: http://www.flickr.com/photos/walkingsf/5351830905/

    The speeds definitely appear to be slower and steadier now than before. I think 14th and 15th Streets must be part of a different synchronized system that keeps them from being part of this.

  • Eric – definitely when you are headed North, at 13 MPH, you get to the light just when it turns green – until you get to 15th. 15th turns green well in advance of arrival at 13 MPH, and 14th even more so. When I hit 16th Street, I put the hammer down.

  • Dave

    Great article and thread. Eric, I timed the lights and found the cycle is set for 60 seconds exactly, 32 seconds green and 28 seconds red (including yellow), for an actual speed of 13.2 miles per hour, not 13.0 as implied by the signs. The cycle would have to be 66 seconds long to achieve a 13.0 mph speed.

    I’m surprised nobody has commented that 13 mph is a little fast for the street. Maybe it’s because we’re mostly relatively young and fast cyclists. But I find that in the southbound direction, from 18th to 24th, I have to pedal hard on my rusty cruiser to keep up with the lights, and if i have to slow and lose momentum to maneuver around a turning car, forget it. I catch a red. If we’re trying to build a network for everyone from the ages of 8 to 80, I think we should reduce the green wave speed to 12 mph.

    That’s the standard in Copenhagen: (http://www.international.fhwa.dot.gov/pubs/pl10010/ch03.cfm) and in this famous video of Odense, the speed is just 9 mph! (too slow)

  • I ride down Valencia every morning from 20th to 14th. Have been loving the green wave. But this morning, I was totally thrown off. The wave wasn’t in effect. I stopped at every light between 19th and 16th. I mean, I’m okay with that (no outrage here), but I had come to expect the wave. Now I’m wondering: Was today just a fluke, or is the wave going away?

  • Luke

    13 MPH is too slow to be useful for utility bicyclists on any flat corridor. To be competitive with other modes, 18 MPH would be much more reasonable, since much of the reason that bicycles move slower than that is because they have to decelerate and accelerate so often. I guess I’d be OK going down to 15 or 16, but if that feels fast for you, then you’re probably not making a trip where travel time is that important.

    I used to commute up Mission Street from downtown out towards Civic Center. The signals were timed for at least 20 MPH and I loved it. THAT is how bicycling competes with driving.

  • mikesonn

    Do you ride with a speedometer? 13 mph is just fine.

  • Anonymous

    It’s not a competition, and though biking is a fast and reliant way of getting around town, people bike for all kinds of reasons. Thinking that it’s all about speed and competing with driving reveals a level of privilege that assumes people have an equal choice in transportation options and pick the fastest.

    With muni speeds of 7 mph 13 is still almost twice as fast, so even if speed was the biggest reason for biking, there’s a huge pool of potential riders on transit, especially overcrowded routes that Muni is unable to improve as quickly as they’d like.

  • mikesonn

    Not to mention: parking, fresh air, gas, maintenance, parking, etc.

  • Anonymous

    A ‘utility cyclist’ who wants to travel north-south through the Mission at an average speed of 20mph can choose to dance with the cars on any number of parallel streets, but Valencia is not one of them. Valencia’s bike infrastructure, including the green wave light cycle, is geared to average cyclists’ speeds.

  • If 13 MPH is so slow, please tell us all why there are so many cyclists on Valencia?

  • I can do 13 mph going downhill easily enough (towards 18th street from either direction) but have a hard time making the lights on the uphill stretch from 18th to 22nd st. I realize I’m not the speediest of bicyclists. Heck, my top speed is 18 mph even downhill on 14th street when I really, really want to make the light. Some bicyclists pass me on Valencia, but, amazingly enough, I also from time to time pass other bicyclists. Just who should Valencia be timed for? If I had my druthers, I would lower it to 12 mph, at least between 18th and 22nd. Green wave speed in Copenhagen is 20 kilometers per hour, or 12.4 mph.

    To say that someone’s travel time is not important if they can’t bike 20 mph is to show a certain amount of basic intolerance for most of the human race.